Credit

Caption

Oblique section of rhinoceros horn, polarised light microscopy. Horn is composed of layers of keratin (the same substance as forms hair and nails). In addition to hair, most land mammals produce a type of hard keratin, known as horny keratin, in the form of nails, hooves, claws, horns and quills. Claims that powdered rhino horn can cure cancer and increase virility have led to many rhino deaths, despite attempts at protection. Magnification: x14 at 10cm wide.